Mount for an Optical Structure and Method of Mounting an Optical Structure Using Such Mount

ABSTRACT

An improved mount for, and method of mounting an, optical structure is provided. The mount has a protruding member extending from a surface of the optical structure, a base element having a mounting structure for mounting the mount to another structure and an upper element extending from the base element having a first opening extending therethrough for receipt therein of at least a portion of the protruding member. The first opening defines first and second arms, each of the arms comprising a head portion and each of the head portions ending at an end. A second opening in the upper element extends through one of the head portions and the end thereof in a direction toward the other head portion, while a third opening exists in the upper element through the end of the other head portion in an orientation substantially opposite to and in communication with the second opening so that a tightening mechanism received through the second opening can be received into the third opening. Tightening of the tightening mechanism into the third opening causes the ends of the head portions to draw toward each other so that the first opening of the upper element tightens around the at least a portion of the protruding member.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/791,564 filed Apr. 12, 2006, the entirety of the disclosure of which application is incorporated herein by reference.

BACKGROUND OF THE INVENTION

This invention relates to the field of mounts for optical structures, including but not limited to, reflective panels, hollow retroreflectors and solid retroreflectors.

Optical structures such as, but not limited to, reflective panels (mirror panels), hollow retroreflectors and solid retroreflectors are old in the art. Solid retroreflectors are solid cubes of glass wherein adjacent sides of the cube are substantially perpendicular to each other and three of the sides that meet at a common corner are polished to have a high degree of flatness. Hollow retroreflectors are made of three mirror panels joined together preferably having optically flat reflective surfaces disposed at right angles to each other, and meeting at what can be described as a common inside corner of an imaginary cube. Both solid and hollow retroreflectors in general have the essential property of causing incident and reflected light rays to travel along substantially parallel paths.

When hollow retroreflectors are assembled for high accuracy and precision it is important to maintain the mutual perpendicularity of the reflective surfaces and sometimes essential to ensure that the retroreflector as a whole does not move. The perpendicularity of the reflective surfaces is affected by external stresses. With regard to high accuracy and precise reflective panels, such as mirror panels to be used for high accuracy purposes, it is also important to try and maintain as optically flat as possible the reflective surface of the panel.

Examples of external stresses that can affect the optical flatness of a reflective panel and/or the perpendicularity of reflective surfaces of abutting reflective panels of a hollow retroreflector, are thermal expansion or contraction of the substrate material from which the panels are made, deflection caused by curing of the adhesives used to join elements together and/or to join the retroreflector to its mount and/or the mass of the panels themselves. Accordingly, it would be desirable to assemble together the elements of a hollow retroreflector and/or to assemble a reflective panel to a mount, in such a manner as to reduce these stresses. It would also be desirable that the manner of mounting a retroreflector to its mount not add to these stresses, but nevertheless, securely retain the retroreflector on the mount. Examples of hollow retroreflector mounts which have proven successful in maintaining the reflective surfaces in their perpendicular orientations are found in U.S. Pat. No. 3,977,765, to Morton S. Lipkins, U.S. Pat. No. 5,122,901, to Zvi Bleier, and U.S. Pat. No. 5,335,111, also to Bleier.

The present mount also achieves secure mounting of the optical structure in a manner designed to help eliminate deflective stresses on the reflective surface(s) of the structure caused by the mounting of the retroreflector to its mount.

The mount also allows for easy and secure mounting of the optical structure onto a support structure.

SUMMARY OF THE INVENTION

In accordance with the invention, an improved mount for, and method of mounting an optical structure is provided. The mount has a protruding member extending from a surface of the optical structure, a base element having a mounting structure for mounting the mount to another structure and an upper element extending from the base element having a first opening extending therethrough for receipt therein of at least a portion of the protruding member. The first opening defines first and second arms, each of the arms comprising a head portion and each of the head portions ending at an end. A second opening in the upper element extends through one of the head portions and the end thereof in a direction toward the other head portion, while a third opening exists in the upper element through the end of the other head portion in an orientation substantially opposite to and in communication with the second opening so that a tightening mechanism received through the second opening can be received into the third opening. Tightening of the tightening mechanism into the third opening causes the ends of the head portions to draw toward each other so that the first opening of the upper element tightens around the at least a portion of the protruding member.

The method of mounting the optical structure onto the mount is to form an optical structure having a reflective surface and a portion of the mount comprising a protruding member extending from a back surface of the optical structure, wherein the protruding member is either integrally formed with, or bonded to, the back surface of the optical structure. Forming the remainder of the mount comprising a base element having a construction for allowing the mount to be mounted to another structure, the mount further having an upper element having a first opening extending therethrough, such first opening forming two arms each having a head portion and ending at ends thereof. Sliding the first opening of the mount over at least a portion of the protruding member. Tightening the first opening of the mount around the protruding member by inserting a tightening mechanism into a second opening located through one of the head portions of the mount and by further inserting and tightening the tightening member into a third opening in the other head portion of the mount so that the tightening member draws the two ends of the head portions toward each other thereby contracting the first opening of the mount around the protruding member of the optical structure.

Accordingly, it is an object of the invention to provide an improved mount for an optical structure.

Another object of the invention is to provide an improved mount for an optical structure which causes minimal external stresses to the reflective surfaces of the optical structure.

Still another object of the invention is to provide an improved mount for an optical structure wherein the mount achieves reductions in movement of the optical structure in order to achieve higher-accuracy distance measurements.

Yet a further object of the invention is to provide an improved mount for an optical structure wherein the mounting of the mount and optical structure to a support structure is easy and secure.

It is even a further object of the invention to provide an improved method of mounting an optical structure using the improved mount.

Other objects of the invention will in part be obvious and will in part be apparent from the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

For a fuller understanding of the invention, reference is made to the following description taken in connection with the accompanying drawings, in which:

FIG. 1 is an exploded perspective view of a mount, optical structure and screw, made in accordance with the invention;

FIG. 2 is a perspective view of the structures of FIG. 1 as joined together; and

FIG. 3 is a cross-sectional view taken along line 3-3 of FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to the figures, a mount for an optical structure made in accordance with the invention is generally designated at 10. In the particular case of the figures of this application, the optical structure portrayed is that of a hollow retroreflector, which will hereinafter generally be designated in the figures at 20. It is of course to be understood that other optical structures are anticipated to be compatibly used with mount 10, including but not limited to, individual mirror panels (not shown) and/or roof mirrors (not shown) and/or solid retroreflectors (not shown).

Retroreflector 20 is preferably made of fused quartz or fine annealed Pyrex, while mount 10 is preferably made of a metal alloy having a very low coefficient of thermal expansion, such as INVAR or aluminum.

Hollow retroreflector 20 is comprised of a first panel 30, a second panel 40, and a third panel 50. Each of the panels 30, 40 and 50 has a corresponding reflective surface 32, 42 and 52 (not specifically shown). The higher the degree of optical flatness achieved in surfaces 32, 42 and 52 will in part determine the accuracy of the corresponding panels 30, 40 and 50. Panels 30, 40 and 50 are disposed substantially at right angles to each other so that reflective surfaces 32, 42 and 52 are also disposed substantially at right angles to each other. Each of panels 30, 40 and 50 also has non-reflective, back surfaces 34, 44 and 54 (not specifically shown) which are opposite to reflective surfaces 32, 42 and 52.

As with all hollow retroreflectors, retroreflector 20 is designed to receive an incoming (incident) light ray (not shown) and reflect the light ray off of the reflective surfaces 32, 42 and 52 and out from retroreflector 20 along a path substantially parallel to the incident light ray. Of course, the incident light ray can initially strike any one of the reflective surfaces without bearing upon the accuracy of the parallelism of the reflected light ray. The accuracy tolerances for retroreflector 20 will almost always depend upon the function to be performed by retroreflector 20. If high degrees of accuracy; i.e., parallelism of the incident and reflected light rays, is a primary purpose of retroreflector 20, then high degrees of precision must be created and maintained with respect to the flatness of and perpendicularity of reflective surfaces 32, 42 and 52.

One construction for a hollow retroreflector is as disclosed in U.S. Pat. No. 3,663,084 to Morton S. Lipkins. If the construction shown in the '084 patent is used herein, then each of panels 30, 40 and 50 of hollow retroreflector 20 has at least first and second sides 36 and 38, 46 and 48 and 56 and 58, respectively. The first and second sides of each of the panels are substantially perpendicular to each other and to each of the other sides of the other panels. As is seen in the figures, second side 48 of panel 40 is abutted against and adhered to reflective surface 32 of panel 30, second side 38 of panel 30 is abutted against and adhered to reflective surface 52 of panel 50, and second side 58 of panel 50 is abutted against and adhered to reflective surface 42 of panel 40. Accordingly, each of panels 30, 40 and 50 is simultaneously an abutting panel at second sides 38, 48 and 58, and an adjacent panel at first sides 36, 46 and 56.

Turning now to a discussion of mount 10, it is seen from the figures that mount 10 has an upper element 60 and a base element 100.

As seen in the figures, base element 100 has extending therein an opening 110. Opening 110 preferably extends through a bottom surface 112 of base 100, but may be placed anywhere on base 100. Opening 110 is preferably threaded to receive a correspondingly threaded member (not shown) extending from some type of support structure (not shown). However, it is also to be understood that instead of having opening 110, base element 100 may have an outwardly extending member (not shown) which would in turn be received into a cooperating opening on a support structure (not shown). In this instance also it is preferred that the extending member and support opening both be threaded to allow for a more secure connection between the two. Additionally, other mounting constructions are intended to be encompassed in the invention, such as the use of a clamp from the support structure to securely hold base element 100, as are other constructions.

Turning now to a discussion of upper element 60 of mount 10, it is seen that in a preferred embodiment upper element 60 has an opening 62 extending therethrough. In the embodiment shown herein opening 62 is circular and such a circular opening is preferred, but not mandatory, it being anticipated by the invention herein that opening 62 may be any geometric shape. It is also seen that opening 62 of upper element 60 creates two arms 64 and 65, each having a respective head portion 67 and 69. Head portion 67 ends at end 70, while head portion 69 ends at end 72. Ends 70 and 72 do not touch and have a gap 68 extending therebetween. Through head 69 extends opening 74, through which screw/bolt/tightening mechanism 80 (hereinafter “element 80”) is received. Opening 74 extends completely through head 69 and end 72 of head 69. As is best shown in FIG. 3, a corresponding and communicating opening 75 extends through end 70 of head 67, so that element 80 is able to be received therein. Assuming element 80 is threaded and that at least opening 75 is also threaded, then as element 80 is tightened into opening 75, ends 70 and 72 are drawn together. As ends 70 and 72 draw together, opening 62 of element 60 becomes smaller; i.e., the diameter lessens, thereby creating a clamping force against protruding member 90 of panel 30, discussed in more detail below. It is also to be understood herein that some, or all of, opening 74 may be correspondingly threaded to receive element 80.

To help secure element 80 within the opening in end 70, all of, or at least a portion of, opening 74 may also be correspondingly threaded. In the figures shown, element 80 is a threaded bolt having an Alan wrench opening in its head for tightening and loosening element 80, as is known in the art. Other elements 80 are anticipated herein; such as, but not limited to, screws and/or bolts having Philips or flat head openings. Other manners of tightening the clamping force of opening 62 by bringing ends 70 and 72 together are also anticipated herein, the primary inventive concept being the mounting of mount 10 through opening 62 onto protruding member 90. As way of a further example, another embodiment of the invention may involve no element 80 and no gap 68 between ends 70 and 72. Instead, opening 62 may be continuous and sized so that a little adhesive applied between the outer surface 92 of protruding member 90 allows opening 62 to be adhered to surface 92.

Turning now to a more detailed discussion of member 90, panel 30 may be formed such that member 90 is an integrally extending part of panel 30 or member 90 may be a separate member that is bonded to back surface 34 of panel 30. In the preferred embodiment, bonding refers to fusing or adhering member 90 to back surface 34 of panel 30. As seen in the figures, member 90 is circular in cross section to conform to opening 62 of mount 10. However, as has been previously discussed, if opening 62 takes a different shape, member 90 would take the same shape.

The method of mounting optical structure 20 onto mount 10 is to form an optical structure having a reflective surface and a protruding member extending from a back surface of the optical structure, wherein the protruding member is either integrally formed from, or bonded to, the back surface of the optical structure. Forming a mounting member having a base element having a construction for allowing the mounting member to be mounted to another structure, the mounting member further having an upper element having a first opening extending therethrough, such first opening forming two arms each having a head portion and ending at ends thereof such that the ends are preferably separated by a gap therebetween at least when the mounting member is not attached to the optical structure. Sliding the first opening of the mounting member over the protruding member of the optical structure. Tightening the first opening of the mounting member around the protruding member by inserting a tightening mechanism into a second opening located through one of the head portions of the mounting member and by further inserting and tightening the tightening member into a third opening in the other head portion of the mounting member so that the tightening member draws the two ends of the head portions together thereby contracting the first opening of the mounting member around the protruding member of the optical structure. The tightening member preferably being a threaded bolt which is received into the third opening and the third opening also being threaded. As previously stated above, the second opening of the mounting member may also be threaded in whole or in part along its length.

The manner of mounting described herein is an improvement over prior mounting manners and is equally good, if not better, at preventing distortion of reflective surface 32 (and therefore of reflective surfaces 42 and 52) so as to help maintain reflective surfaces 32, 42 and 52 in their substantially flat and substantially perpendicular relationship to each other. In particular, with the manner of mounting described herein there are no distortional stresses applied on reflective surface 32 by either the securing forces exerted by the contracting of first opening 62 around protruding member 90 or due to contraction or expansion of the mounting member due to temperature change, or other reasons. In particular, due to the orientation of protruding member 90 to reflective surface 32 and further since any such contracting or distortional forces exerted on member 90 from the mounting member are applied in directions/planes that are parallel to reflective surface 32, and not perpendicular to it, such forces will only nominally, if at all, effect the optical flatness of surface 32.

It will also be seen that the manner of mounting described herein achieves substantial rigidity between optical structure 20 and mount 10. Further, as described in the immediate above paragraph, the preferred low coefficient of thermal expansion metal alloy material which makes up mount 10 significantly reduces the effects of thermal expansion/contraction of mount 10 so as to substantially minimize these effects on the accuracy of optical structure 20.

It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained, and, since certain changes may be made in the above constructions without departing from the spirit and scope of the invention, it is intended that all matter contained in the above description and shown in the accompanying drawings shall only be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween. 

1. A mount for an optical structure, comprising: a protruding member extending from a surface of said optical structure; a base element having a mounting structure for mounting said mount to another structure; an upper element extending from said base element having a first opening extending therethrough for receipt therein of at least a portion of said protruding member, said first opening defining first and second arms, each of said arms comprising a head portion and each of said head portions ending at an end; a second opening in said upper element extending through one of said head portions and said end of said one of said head portions in a direction toward said other head portion; a third opening in said upper element through said end of said other head portion which third opening is substantially opposite said second opening so that a tightening mechanism received through said second opening can be received into said third opening; wherein tightening of said tightening mechanism into said third opening causes said ends of said head portions of said first and second arms of said upper element to draw toward each other so that said first opening of said upper element tightens around said at least a portion of said protruding member.
 2. A mount as recited in claim 1, wherein said ends of said head portions do not touch each other thereby defining a gap therebetween.
 3. A mount as recited in claim 1, said protruding member having a substantially circular shape.
 4. A mount as recited in claim 1, said protruding member being of any geometric shape.
 5. A mount as recited in claim 1, said third opening being threaded for receipt therein of a correspondingly threaded end of said tightening mechanism.
 6. A mount as recited in claim 5, at least a portion of said second opening being threaded.
 7. A mount as recited in claim 1, said upper element and said base element being integrally formed.
 8. A mount as recited in claim 7, said integrally formed upper and base elements of said mount being of a metal alloy having a low coefficient of thermal expansion.
 9. A mount as recited in claim 8, said metal alloy being aluminum.
 10. A mount as recited in claim 8, said metal alloy being INVAR.
 11. A mount as recited in claim 1, wherein said optical structure is taken from the group consisting of: hollow retroreflectors, solid retroreflectors, mirror panels and roof mirrors.
 12. A mount as recited in claim 11, said optical structure comprising at least one mirror panel having a reflective surface and a back surface, said back surface extending in a plane substantially parallel to a plane of said reflective surface.
 13. A mount as recited in claim 12, said protruding member integrally formed with said back surface of said at least one mirror panel.
 14. A mount as recited in claim 12, said protruding member bonded to said back surface of said at least one mirror panel.
 15. A mount as recited in claim 14, wherein said bonding of said protruding member to said back surface is fusing.
 16. A mount as recited in claim 14, wherein said bonding of said protruding member to said back surface is adhering.
 17. A mount as recited in claim 12, said protruding member and said optical structure made of fused quartz or annealed Pyrex.
 18. A mount as recited in claim 1, said mounting structure comprising a threaded member extending from said another structure for cooperative screwed attachment within a threaded opening in said base element.
 19. A mount as recited in claim 1, said mounting structure comprising a threaded member extending from said base element for cooperative screwed attachment within a threaded opening in said another structure.
 20. A method of mounting an optical structure, comprising the steps of: forming an optical structure comprising at least one mirror panel, said at least one mirror panel having at least one reflective surface and at least one back surface substantially opposite said reflective surface, wherein said back surface has a protruding member extending therefrom, said protruding member being part of a mount for mounting said optical structure; forming an upper element of said mount comprising a first opening extending therethrough, such first opening forming two arms in said upper element, each of said two arms having a head portion and ending at an end thereof, sliding said first opening of said mount over at least a portion of said protruding member; tightening said first opening of said upper element of said mount around said at least said portion of said protruding member by inserting a tightening mechanism into a second opening located through one of said head portions of said upper element and by further inserting and tightening said tightening mechanism into a third opening in said other head portion of said upper element so that said tightening mechanism draws said two ends of said head portions toward each other.
 21. A method of mounting an optical structure as recited in claim 20, further comprising the step of integrally forming said protruding member with said at least one mirror panel.
 22. A method of mounting an optical structure as recited in claim 20, further comprising the step of bonding said protruding member to said back surface of said at least one mirror panel.
 23. A method of mounting an optical structure as recited in claim 22, said bonding comprising fusing.
 24. A method of mounting an optical structure as recited in claim 22, said bonding comprising adhering.
 25. A method of mounting an optical structure as recited in claim 20, further comprising the step of forming a base element of said mount with said upper element of said mount.
 26. A method of mounting an optical structure as recited in claim 25, said base element being formed integrally with said upper element.
 27. A method of mounting an optical structure as recited in claim 25, further comprising the step of forming supporting means for said base element of said mount for securing said optical structure to a support structure.
 28. A method of mounting an optical structure as recited in claim 27, wherein said supporting means comprising a threaded member extending from said support structure for cooperative screwed attachment within a threaded opening in said base element.
 29. A method of mounting an optical structure as recited in claim 27, wherein said supporting means comprising a threaded member extending from said base element for cooperative screwed attachment within a threaded opening in said support structure. 